Re: [BUG] [PATCH] org-babel-execute-buffer: Prevent executing non-code blocks [9.6.20 ( @ /home/cassou/.emacs.d/lib/org/lisp/)]

[Ihor Radchenko <yantar92@posteo.net>]

Damien Cassou <damien@cassou.me> writes:

> Ihor Radchenko <yantar92@posteo.net> writes:
>> Thanks for the patch, but it is not obvious that skipping src blocks
>> that cannot be executed is always a good idea.  Consider, for example,
>> that some blocks are used as input for other blocks. Then, failing to
>> execute them means that other blocks may have unpredictable side
>> effects.
>
>
> I don't understand your position. Without this patch, executing
> `org-babel-execute-buffer' will just crash if a block can't be
> executed. What problem can skipping those could cause?

For example, consider

#+begin_src bash
mkdir foo
#+end_src

#+begin_src emacs-lisp
(write-file "foo/result")
#+end_src

The second block relies upon side effects of the first block.
However, if ob-shell is not loaded, with your patch, the side effect
will not happen.

One can construct more nasty examples when not executing prior block
leads to unexpected or even damaging results.

>> May you please provide a concrete use-case when skipping some src code
>> blocks is desired?
>
> I use text-mode blocks to represent output of bash scripts as in:
>
>     #+name: repo-test-check
>     #+begin_src sh :exports both :results output raw :wrap SRC text
>       git log --oneline
>     #+end_src
>     
>     #+RESULTS: repo-test-check
>     #+begin_SRC text
>     cfd2b (HEAD -> main) Empty
>     #+end_SRC
>
> The second block can't be executed because no
> `org-babel-execute:text` function exists.

Why not simply adding :eval no header argument?

The problem with testing that `org-babel-execute:<lang>' function exists
is that we cannot distinguish between languages that cannot and should
not be executed and babel backends that are not loaded for some reason.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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